Polyepoxide compositions for rendering synthetic fibers free and undiscolored and process of utilizing same



United States Patent ()fifice 3,371,052 Patented Feb. 27, 1968 ABSTRACTOF THE DISCLOSURE A composition of matter for rendering a synthetictextile fiber static free and undiscolored being comprised of apolyepoxide, a polyamine, and a reducing agent which is applied to thefiber in the form of an aqueous emulsion.

Synthetic fibers when coming into contact with foreign objects tend tocollect static electrical charges thereon which is objectionable duringthe manufacture and wearing thereof. The accumulation of static chargesthereon prevents the finished synthetic fibers from draping like cottonor wool and causes the same to cling uncomfortably to the wearer. Thestatic charges also attract dust and lint to the fabric. It is wellknown in the art that polyamines are effective temporary antistaticagents and when associated with the fibers which comprise a fabric inthe presence of a polyepoxide, the polyamine molecules polymerizethereon and become durably attached thereto.

The methods and compositions are clearly shown in US. Patent No.3,021,232 to Pretka and US. Patent No. 2,982,- 751 to Anthes,respectively. However, it has been found that when a fiber is treatedwith a polyamine compound, a discoloration results which is undesirableand which lowers the commercial value of the fiber. An aftcrwash may beapplied but this is only partially effective for it does not remove allthe discoloration. It also is an additional operation which is objectedto as being time and money consuming. It is to this problem thatattention of this application will be directed.

Therefore, an object of this invention is to provide a novel processwhich will impart to a synthetic textile fabric antistatic propertieswithout discoloring the same.

Another object of this invention is to provide a novel composition ofmatter Which renders antistatic protection to a synthetic textile fabricwithout'discoloring the same.

A further object of this invention is to provide synthetic fibers whichretain their original color after being associated with an antistaticagent.

These and other objects will become apparent in the course of thefollowing specifications and claims.

In accordance with a preferred embodiment of the present invention, asynthetic textile fiber is provided with durable antistatic propertiesby continuously associating the fiber, either during the spinningthereof or when the fiber is in fabric form, with an aqueous polyamine/epoxy resin compound which also contains a third ingredient. This thirdadditive prevents the discoloration of the fiber by acting as a reducingagent.

The use of these antistatic agents, in accordance with the presentinvention, effects improvements in the characteristics of acrylonitrilepolymers and articles produced therefrom. This invention is applicablenot only to polyacrylonitrile, but also to copolymers, interpolymers andblends thereof, particularly those containing at least 80 -When themoisture content percent by weight of polymerized or copolymerizedacrylonitrile. Such polymeric materials include acrylonitrilefiber-forming polymers with readily dyeable basic copolymers, the blendhaving an overall polymerized acrylonitrile content of at least percentby weight.

An acrylic fiber may be formed by extruding a typicalacrylonitrile-based spinning dope through a conventional spinneretteinto an aqueous coagulation bath wherein the dope hardens into afilament. After the fibers were washed and stretched as they were drawnup a hot water cascade, they are heated and partially dried on a set ofdrying rolls. of the fiber was approximately 20 percent by weight andthe temperature of the filaments had reached approximately C., they wereimmersed in an aqueous emulsion which contains (a) a polyamine,

(b) an epoxide resin,

(c) a reducing agent, and (d) a lubricant Where the aqueous emulsion isappled to a fabric by padding, or the like, the lubricant may beeliminated for there is no problem of the fibers wrapping around thedrying rolls. The mixture preferably contains a dispersing oremulsifying agent which insures a more homogeneous suspension of theseveral ingredients. The temperaures of the suspension is generally heldat below 40 C. in order to prevent premature polymerization.

Also, this invention may be used in combination with polyester fibers. Afiber was formed by extruding a typical polyester melt, such aspolyethylene terephthalate; through a conventional spinnerettedownwardly through a chimney where the melt was air quenched and washardened into filaments. The fibers were converged and collected on abobbin as undrawn yarn. A number of bobbins were then combined and a towwas formed by continuously pulling the yarn therefrom. The tow washeated to at least 40 C. by being passed under a hot waterspray. Thefibrous tow then passed into a draw zone Where the temperature thereofwas increased to 80 C.90 C. by another hot water spray or by a finishingsolution and was elongated from four to five times its original length.After the tow has been drawn, it is immersed in, padded, or sprayed withan aqueous antistatic emulsion which becomes polymerized thereon whenheated to about C. The dried fibrous tow was then cut to staple lengthsand processed according to conventional techniques.

The use of polyamine compounds as antistatic agents is controlled by thepH value of the mixture, however, the pH value is not necessarily alimiting factor. The effec tiveness is strictly dependent on the pHvalue for above seven, the effectiveness is much greater than belowseven, although the lower the pH the less the color of the fiber isaffected. Where the mixture is given a high pH value the fiber becomesdiscolored upon association therewith. It has been found that a pH ofabove seven is needed to functionally justify the use of the polyamineas an antistat; therefore, to inhibit discoloration, a reducing agent isused. The reducing agent functions to destroy the discoloration which isa characteristic by-product upon treating synthetic fibers withpolyamines. Almost any reducing agent may be used; however, it has beenfound that the most effective ones are sodium bisulfite, sodiumhydrosulfite, sodium sulfoxylate, formaldehyde, and oxalic acid. Oxalicacid may be used for adjusting the pH of the emulsion as well as forpreventing the discoloration of the treated fiber.

An example of a polyamine in accordance with the present invention is apolyamine having the formula:

i it? it a tma m?- HH HHH HH and a mixture of these radicals wherein Ris a lower alkyl radical, -E- is a divalent radical selected from thegroup of desoxy A radicals (i.e., an -A radical without its oxygenatom), m is a whole number from about 5 to 85 and n is a whole numberfrom about 1 to about 50. The preparation of these polyarnines isdiscussed in Belgian Patent No. 554,506, granted Jan. 25, 1957. Suchmaterials may be purchased on the open market from Onyx ChemicalCompany, 190 Warren Street, Jersey City, N.J., under the trademarkAston.

The epoxide resin referred to above can be prepared by condensingepichlorohydrin with a polyol. A typical example is the condensationproduct (with elimination of HCl) of glycerine and epichlorophydrin. Thepreparation thereof is described in detail in British Patent No.780,288, dated July 31, 1957. Such a material is available on the openmarket under the trademark Eponite 100.

When an aqueous bath is prepared from water, a polyamine, an epoxyresin, and a reducing agent, it is desirable to add thereto a dispersingagent to insure a thorough dispersion of the insoluble Eponite 100.Satisfactory dispersing of emulsifying agents are the aromaticpolyglycol ethers, one example of such being the alkylphenol olyglycolether containing 9.5 moles of ethylene oxide which can be purchased onthe open market under the trade- "mark Neutronyx 600.

The effectiveness of the reducing agents in reducing discoloration waschecked in the manner as set forth below. Where the antistatic emulsionwas applied to a tow, the finished filaments are converted into yarn andthe yarn is knitted into a tubular fabric shape whereupon the fabric isblank dyed by any conventional dyeing process. Where the antistaticemulsion was applied to a finished fabric, it was also blank dyed by aconventional dyeing process. Hereinafter, the testing processes are thesame for both types of samples. The fabric is washed in a Kenmorewashing machine at 100 F. using 0.5 percent Tide detergent for fourminutes or alternatively, a 0.3 percent solution of tetra sodiumpyrophosphate may be used as the detergent. After the tube is removedfrom the Washing machine, it is centrifuged to remove the excessmoisture. The steps of washing the tube in the detergent for fourminutes, centrifuging it and drying it in an air atmosphere with arelative humidity of 35 percent at a temperature of 72 F. are repeated aselected number of times, whereupon the fabric is run on a Hayeck andChromey apparatus to determine the level of static protection afterselected washings. To determine purity (the effectiveness of thereducing agent in preventing discoloration), the fabric is tested by aGeneral Electric spectrophotometer. Such test results are then comparedwith the results obtained on tubes treated with antistaic formulaionswhich do not contain a reducing agent.

The following examples are cited to illustrate the invention. They arenot intended to limit this invention in any way. Unless otherwise noted,parts as expressed in the examples indicate parts by volume.

Example I A sample of acrylic fibers consisting of a copolymer of 93percent acrylonitrile and 7 percent vinyl acetate in the form of a towor fabric were treated by padding, drying,

curing and the like, with an aqueous emulsion having the followingconstituents:

Percent Polyarnine 15.00 Polyepoxide 1.50 Polyglycol ether 0.38 Zincsulfoxylate formaldehyde 2.00

Water 81.12

The above identified emulsion was also applied to a polyester fibersample. The total finish solids constituted at least 0.4 percent of theweight of the fiber. The pH of the above aqueous emulsion was adjustedto between 7 and 8 by hydrochloric acid. Several tests were run whereinthe total finish applied to the fiber was varied over a wide range bychanging the relative concentrations of the finish ingredients whichcomprise the aqueous emulsion. Table I (immediately below) shows theelfect the reducing agent had on purity, purity being determined by theGeneral Electric spectrophotometer.

TABLE I Sample Treatment Purity Acrylonitrile based fabric- Emulsitonwithout reducing 9. 2

agen Do Emulsion with zinc sulfoxylate 5.1

formaldehyde. Polyester fabric Emulsion without reducing 9. 3

agen Do Emulsion with zinc sulfoxylate 5. 3

formaldehyde.

Example 11 The finish solutions applied to acrylonitrile based fibersand polyester fibers as described in Example I were modified bysubstituting 2 percent sodium sulfoxylate formaldehyde for zincsulfoxylate formaldehyde. The remainder of the elements were added inthe proportions of Example I. The samples herein disclosed wereevaluated according to the procedure of Example I and yielded theresults illustrated in Table II.

TABLE 11 Sample Treatment Purity Acrylonitrile based fabric. Emulsionwithout reducing 9. 2

ngon Do Emulsion with sodium sultoxyl- 5. 3

ate formaldehyde. Emulsion without reducing 9. 4

agent. Emulsion with sodium sulfoxyl- 5. 1

ate formaldehyde.

Example III The finish solutions applied to acrylonitriie based fibersand polyester fibers as described in Example I were modified bysubstituting sodium hydrosulfite for zinc sulfoxylate formaldehyde. Thesamples herein disclosed were evaluated according to the procedure ofExample I and were treated with an aqueous emulsion which was com prisedof the following constituents:

Percent Polyamine 10.00 Polyepoxide 1.00 Polyglycol ether 0.25 Sodiumhydrosulfite 0.50

Water 88.25

Table III illustrates the effectiveness that the reducing agent had onpurity.

TABLE III Sample Treatment Purity Acrylonitrile based fabric. Emulsionwithout reducing 9. 2 Do n iiiiiin with sodium hydro- 6.7 Polyesterfabric Er ri lii sio n without reducing 9. 3 Do Er ii jl si on withsodium hydro- 0. 8

sulfite.

Example IV The finish solutions applied to the acrylonitrile basedfibers and polyester fibers as described in Example I were modified bysubstituting 2.0 percent formaldehyde which is in a 40 percent solutionfor the zinc sulfoxyla-te formaldehyde; the proportions of the remainingelements were left unchanged. The samples herein disclosed wereevaluated according to the procedure of Example I and yielded theresults illustrated in Table IV.

As previously described, a synthetic textile filament in the form of atow or fabric is treated with an aqueous emulsion comprising the mixtureof a polyepoxide, a polyamine and a reducing agent. The concentration ofthe reactants in the suspension may vary widely, however, emulsionscontaining from about 1 percent to about 30 percent by volume ofreactants are generally preferred. Such an emulsion will be able toprovide a synthetic fiber with an adequate amount of antistaticprotection without having the undesirable discoloration which isgenerally present when a synthetic fiber is associated with a polyamine.After the fiber has been associated with the antistatic aqueousemulsion, the reactants are cured thereon by raising the temperaturethereof to 145 C. for six minutes.

Many different modifications of the invention may be made withoutdeparting from the scope and spirit thereof. It is contemplated thatvariations may be made in the percentages of the compounds used withoutgreatly altering the antistatic characteristics of the fiber; therefore,the applicant does not wish to be bound by the numbers exactly as theyappear herein.

I claim:

1. A composition of matter for rendering synthetic fiber static free andundiscolored, said composition comprising:

(a) a polyepoxide obtained as a condensation product of epichlorohydrinand a polyol,

(b) a polyamine having the formula H(D--A -E),,DH where D is a divalentradical terminating in amino nitrogen, --A is a divalent radicalselected from the group consisting of 3. A composition of matteraccording to claim 1 wherein the reducing agent is sodium sulfoxylateformaldehyde.

4. A composition of matter according to claim 1 wherein the reducingagent is sodium hydrosulfite.

5. A composition of matter according to claim 1 wherein the reducingagent is formaldehyde.

6. A composition of matter according to claim 1 wherein the reducingagent is oxalic acid.

7. A process of rendering an undiscolored, static free fiber comprisingthe steps of applying to the fiber a mixture in the form of an aqueousemulsion of (a) a polyepoxide obtained as a condensation product ofepichlorohydrin and a polyol,

(b) a polyamine having the formula amino nitrogen, A- is a divalentradical selected from the group consisting of and a mixture of theseradicals wherein R is a lower alkyl radical, E is a divalent radicalselected from the group of desoxy A- radicals, in is a whole number fromabout 5 to '85 and n is a whole number from about 1 to about 50, and

(c) a reducing agent selected from the group consisting of oxalic acid,zinc sulfoxylate formaldehyde, sodium sulfoxylate formaldehyde, sodiumhydrosulfite, and formaldehyde, and polymerizing said mixture on saidfiber.

8. A process according to claim 7 wherein the reducing agent is zincsulfoxylate formaldehyde.

9. A process according to claim 7 wherein the reducing agent is sodiumsulfoxylate formaldehyde.

10. A process according to claim 7 wherein the reducing agent is sodiumhydrosulfite.

11. A process according to claim 7 wherein the reducing agent isformaldehyde.

12. A process according to claim 7 wherein the reducing agent is oxalicacid.

13. A process according to claim 7 wherein the textile fiber iscomprised of synthetic fibers which are chosen from the group consistingof polymerized acrylonitrile and a copolymerized mixture ofacrylonitrile and up to about 15 percent by weight of at least onemonomer copolymerizable therewith.

14. A process according to claim 7 wherein the textile fiber is formedfrom a polyester.

15. A process according to claim 7 wherein the said synthetic textilefiber is in fabric form.

16. A process according to claim 7 wherein the mixture is at a pH ofabove 7.0.

References Cited UNITED STATES PATENTS 2,5 00,449 3/ 1950 Bradley 260 -22,878,214 3/1959 Holmes et a1. 26045.7 2,878,221 3/1959 Jenkins et a1.260--45.7 2,965,517 12/ 1960 Albrecht et a1. 260-2 WILLIAM H. SHORT,Primary Examiner. T. PERTILLA, Assistant Examiner.

